New Holland TRANS 116 – Transmission Controller (TRANS / TCU): C1-2 clutch solenoid coil or its wiring is shorted to power

The controller is detecting +12 Volts on the circuit when the solenoid driver is commanded off, which points to either a wiring harness short to a power source or an internal failure within the solenoid coil itself.

• TG210
• TG230
• TG255
• TG285
• TG305
• T8010
• T8020
• T8030
• T8040
• T8050
• T9000 Series
• MX Magnum
• Steiger series

1. 1

   Inspect the wiring harness running from the transmission controller to the C1-2 clutch solenoid for abnormal routing, bare wires, chafing, or loose connections

2. 2

   Disconnect the electrical connector at the C1-2 solenoid and at the transmission controller, then use a multimeter to check the signal wire for continuity to a 12V power source (wiring short cause)

3. 3

   Measure the resistance of the solenoid coil and compare it to a known good solenoid on the same valve block (internal solenoid short cause)

4. 4

   Swap the transmission controller with a known good spare, if available, to rule out a failed controller driver (rare cause)

1. 1

   Park the tractor on a level surface, engage the parking brake, and turn off the engine.

2. 2

   Locate the transmission control valve block on the side of the transmission housing and identify the specific C1-2 clutch solenoid.

   Refer to the service manual diagram for exact spool location.

3. 3

   Thoroughly clean the area around the solenoid to prevent dirt and debris from entering the hydraulic valve body.

4. 4

   Disconnect the electrical connector from the C1-2 solenoid.

5. 5

   Remove the retaining bolt and bracket holding the solenoid in place.

6. 6

   Carefully pull the solenoid valve assembly out of the transmission valve block bore.

7. 7

   Lubricate the O-rings on the new solenoid valve with clean transmission/hydraulic fluid.

8. 8

   Insert the new solenoid into the bore, reinstall the retaining bracket, and torque the bolt to OEM specifications.

9. 9

   Reconnect the electrical connector.

10. 10

    Clear the fault codes using the tractor's diagnostic menu or a service tool.

11. 11

    Perform a transmission clutch calibration procedure to ensure the controller learns the engagement characteristics of the new solenoid.